| This study establishes a foundation for screening drought\|resistant safflower germplasm resources and defining the identification criteria and evaluation methods for safflower drought resistance. A total of 236 safflower germplasm resources were studied, and normal irrigation (CK) and drought treatment groups were set up: no irrigation during the whole reproductive period (T1), and one irrigation at the first flowering stage (T2). Safflower plant height, yield per plant and oil content of seeds were measured, and drought resistance was identified, screened and comprehensively evaluated. The results showed that the coefficients of variation among the test materials ranged from 0.158 to 1.617, the coefficients of variation of drought resitance coefficient values ranged from 0.118 to 1.071, and the coefficients of variation of drought resistance index values ranged from 0.131 to 1.104. The drought resistance of the test materials was initially categorized into three grades by the comprehensive drought resistance index ranking. The quantitative relationship analysis showed that the fitting accuracy (R2=0.9078) was higher in treatment 1 group, while the fitting accuracy (R2=0.6235) was lower in treatment 2 group. Gray correlation analysis, principal component and affiliation function analysis showed that the mean variance of R2 for treatment 2 group was 0.2843 higher than that of treatment 1 group. Cluster analysis based on the drought resistance comprehensive evaluation values resulted in five categories: strong drought resistant, drought resistant, moderately drought resistant, relatively sensitive and sensitive drought resistant materials. Strong drought resistant materials include ‘23A020’, ‘23A042’, ‘23B035’, and ‘23H005’, etc. A comprehensive evaluation mathematical model was established by stepwise regression analysis equation, and the comprehensive drought tolerance indexes selected for treatment 1 group (R2=0.196) and treatment 2 group (R2=0.195) were plant height, plant height drought tolerance index and yield drought tolerance index. This study provides a theoretical base for screening drought\|resistant safflower germplasm resources, selecting and breeding late\|maturing varieties, and promoting their application in suitable regions. |